Mailman 3 February 2018 - Python-Dev

How is the GitHub workflow working for people?
by Brett Cannon Feb. 27, 2018

Feb. 27, 2018

It's been a year and 10 days since we moved to GitHub, so I figured now is as good a time as any to ask people if they are generally happy with the workflow and if there is a particular sticking point to please bring it up on the core-workflow mailing list so we can potentially address it.

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Disable built-in module import in embedded Python
by Viktor Kovacs Feb. 27, 2018

Feb. 27, 2018

Hi All, I have a question about embedding python in C++. I don't want to create a duplication so I just leave here the existing stack overflow question: https://stackoverflow.com/questions/48992030/disable-built-in-module-import… Do you have any idea how to achieve this? Thanks, Viktor

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Code stability and a big thank you
by Chris Angelico Feb. 26, 2018

Feb. 26, 2018

As part of the discussions on local name binding, I dug up a patch that I sent to python-ideas back in June 2015. That's two and a half years ago, and was based on CPython 3.5. Here's what happened when I attempted to apply it to the current master branch (3.8): $ patch <~/Downloads/scope_hack.patch -p1 patching file Python/compile.c Hunk #1 succeeded at 100 (offset 3 lines). Hunk #2 succeeded at 134 (offset 3 lines). Hunk #3 succeeded at 793 (offset 2 lines). Hunk #4 succeeded at 2824 (offset 432 lines). Hunk #5 succeeded at 2871 with fuzz 2 (offset 430 lines). Hunk #6 succeeded at 3312 (offset 402 lines). Hunk #7 succeeded at 3330 (offset 402 lines). Hunk #8 succeeded at 5442 with fuzz 1 (offset 831 lines). Hunk #9 succeeded at 5457 with fuzz 2 (offset 832 lines). Hunk #10 succeeded at 5520 with fuzz 2 (offset 823 lines). $ And the build ran fine, the test suite didn't gain any new failures (there's no tests for the new functionality, but it didn't break anything else), and my original demo program worked just fine. Thank you to all the CPython core devs for maintaining code that is THIS stable. Stuff happens but there's no unnecessary code churn. Sure, GNU Patch had to do a bit of work to merge in the changes, but it did it completely automatically. You folks are awesome! ChrisA

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3.7.0b2 code cutoff soon!
by Ned Deily Feb. 25, 2018

Feb. 25, 2018

Just a reminder that 3.7.0b2 is almost upon us. Please get your feature fixes, bug fixes, and documentation updates in before 2018-02-26 ~23:59 Anywhere on Earth (UTC-12:00). That's a little over 1.5 days from now. Also, as previously noted, for those of you who asked for and received extensions for a few remaining 3.7.0 features, those extensions expire as of the b2 cutoff so please plan accordingly. Looking ahead, we need to start locking down 3.7.0 so that our downstream users, that is, third-party package developers, Python distributors, and end users, can test their code with confidence that the actual release of 3.7.0 will hold no unpleasant surprises. So please assume that the 3.7.0 ABI will be frozen as of beta 3, in 4 weeks on 2018-03-26, and that only doc updates and the kinds of bug fixes appropriate for a maintenance release should be going into the 3.7 branch after 3.7.0b3 without further discussion. Thanks again for all of your hard work towards making 3.7.0 yet another great release! --Ned -- Ned Deily nad(a)python.org -- []

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Re: [Python-Dev] [Python-checkins] Exhaustively test dataclass hashing when no hash= value is provided. This is in anticipation of changing how non-default hashing is handled. (GH-5834) (GH-5889)
by Eric V. Smith Feb. 25, 2018

Feb. 25, 2018

Thanks. Do you know if this gets backported to 3.7? Eric. On 2/25/2018 1:36 PM, Terry Reedy wrote: > On 2/25/2018 11:56 AM, Eric V. Smith wrote: > >> + # specify any value in the deecorator). > > I fixed this through the web interface. The CI now knows that a comment > change does not need testing. I could not request a review from > ericvsmith though. > > tjr > > > _______________________________________________ > Python-checkins mailing list > Python-checkins(a)python.org > https://mail.python.org/mailman/listinfo/python-checkins

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Re: [Python-Dev] The `for y in [x]` idiom in comprehensions
by David Mertz Feb. 24, 2018

Feb. 24, 2018

FWIW, the nested loop over a single item is already in the language for 15 years or something. It's not that ugly, certainly not enough to need a new 'let' or 'where' keyword that basically does exactly the same thing with 3 fewer characters. On Feb 23, 2018 10:04 PM, David Mertz <mertz(a)gnosis.cx> wrote: On Feb 23, 2018 9:26 PM, "Steven D'Aprano" <steve(a)pearwood.info> wrote: Given a potentially expensive DRY violation like: [(function(x), function(x)+1) for x in sequence] there are at least five ways to solve it. A 6th way is to wrap the expensive function in @lru_cache() to make it non-expensive. [(a, a+1) for x in sequence for a in [function(x)]] It's funny to me how many people, even the BDFL, have said this is tricky to reason about or recognize. I didn't think of it all by myself, but saw it somewhere years ago. It seemed obvious once I saw it. Since then it's something I do occasionally in my code without much need for thought.

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Re: [Python-Dev] How is the GitHub workflow working for people?
by Antoine Pitrou Feb. 24, 2018

Feb. 24, 2018

On Thu, 22 Feb 2018 07:51:17 -0800 Steve Dower <steve.dower(a)python.org> wrote: > It then becomes grunt work for reviewers, who also have to carefully balance encouraging new contributors against preventing the code base from getting worse. That's a fair point I hadn't considered. OTOH the style issues I usually comment on as a reviewer aren't the kind that would be caught by an automated style check (I tend to ask for comments or docstrings, or be nitpicky about some variable or function name). YMMV :-) > I’d rather have a review bot that can detect problems in PRs and comment on them. We can choose to merge anyway and it won’t keep being noisy, but it also saves committers from potentially telling someone their contribution isn’t welcome because of their camelCase. Yeah, that sounds like an interesting feature. Regards Antoine.

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Re: [Python-Dev] The `for y in [x]` idiom in comprehensions
by David Mertz Feb. 24, 2018

Feb. 24, 2018

On Feb 23, 2018 9:26 PM, "Steven D'Aprano" <steve(a)pearwood.info> wrote: Given a potentially expensive DRY violation like: [(function(x), function(x)+1) for x in sequence] there are at least five ways to solve it. A 6th way is to wrap the expensive function in @lru_cache() to make it non-expensive. [(a, a+1) for x in sequence for a in [function(x)]] It's funny to me how many people, even the BDFL, have said this is tricky to reason about or recognize. I didn't think of it all by myself, but saw it somewhere years ago. It seemed obvious once I saw it. Since then it's something I do occasionally in my code without much need for thought.

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Summary of Python tracker Issues
by Python tracker Feb. 23, 2018

Feb. 23, 2018

ACTIVITY SUMMARY (2018-02-16 - 2018-02-23) Python tracker at https://bugs.python.org/ To view or respond to any of the issues listed below, click on the issue. Do NOT respond to this message. Issues counts and deltas: open 6485 (+29) closed 38190 (+37) total 44675 (+66) Open issues with patches: 2530 Issues opened (54) ================== #31355: Remove Travis CI macOS job: rely on buildbots https://bugs.python.org/issue31355 reopened by pitrou #32008: Example suggest to use a TLSv1 socket https://bugs.python.org/issue32008 reopened by christian.heimes #32861: urllib.robotparser: incomplete __str__ methods https://bugs.python.org/issue32861 opened by michael-lazar #32862: os.dup2(fd, fd, inheritable=False) behaves inconsistently https://bugs.python.org/issue32862 opened by izbyshev #32865: os.pipe creates inheritable FDs with a bad internal state on https://bugs.python.org/issue32865 opened by eryksun #32866: zipimport loader.get_data() requires absolute zip file path https://bugs.python.org/issue32866 opened by barry #32867: argparse assertion failure with multiline metavars https://bugs.python.org/issue32867 opened by MaT1g3R #32871: Interrupt .communicate() on SIGTERM/INT https://bugs.python.org/issue32871 opened by porton #32872: backport of #32305 causes regressions in various packages https://bugs.python.org/issue32872 opened by doko #32873: Pickling of typing types https://bugs.python.org/issue32873 opened by serhiy.storchaka #32874: IDLE: Add tests for pyparse https://bugs.python.org/issue32874 opened by csabella #32875: Add __exit__() method to event loops https://bugs.python.org/issue32875 opened by porton #32876: HTMLParser raises exception on some inputs https://bugs.python.org/issue32876 opened by hanno #32877: Login to bugs.python.org with Google account NOT working https://bugs.python.org/issue32877 opened by ruffsl #32878: Document value of st_ino on Windows https://bugs.python.org/issue32878 opened by gvanrossum #32879: Race condition in multiprocessing Queue https://bugs.python.org/issue32879 opened by TwistedSim #32880: IDLE: Fix and update and cleanup pyparse https://bugs.python.org/issue32880 opened by terry.reedy #32881: pycapsule:PyObject * is NULL pointer https://bugs.python.org/issue32881 opened by zhaoya #32882: SSLContext.set_ecdh_curve() not accepting x25519 https://bugs.python.org/issue32882 opened by sruester #32883: Key agreement parameters not accessible https://bugs.python.org/issue32883 opened by sruester #32884: Adding the ability for getpass to print asterisks when passowr https://bugs.python.org/issue32884 opened by matanya.stroh #32885: Tools/scripts/pathfix.py leaves bunch of ~ suffixed files arou https://bugs.python.org/issue32885 opened by hroncok #32886: new Boolean ABC in numbers module https://bugs.python.org/issue32886 opened by smarie #32887: os: Users of path_converter don't handle fd == -1 properly https://bugs.python.org/issue32887 opened by izbyshev #32888: Improve exception message in ast.literal_eval https://bugs.python.org/issue32888 opened by Rosuav #32890: os: Some functions may report bogus errors on Windows https://bugs.python.org/issue32890 opened by izbyshev #32891: Add 'Integer' as synonym for 'Integral' in numbers module. https://bugs.python.org/issue32891 opened by terry.reedy #32892: Remove specific constant AST types in favor of ast.Constant https://bugs.python.org/issue32892 opened by serhiy.storchaka #32893: ast.literal_eval() shouldn't accept booleans as numbers in AST https://bugs.python.org/issue32893 opened by serhiy.storchaka #32894: AST unparsing of infinity numbers https://bugs.python.org/issue32894 opened by serhiy.storchaka #32896: Error when subclassing a dataclass with a field that uses a de https://bugs.python.org/issue32896 opened by John Didion #32897: test_gdb failed on Fedora 27 https://bugs.python.org/issue32897 opened by amitg-b14 #32900: Teach pdb to step through asyncio et al. https://bugs.python.org/issue32900 opened by smurfix #32901: Update 3.7 and 3.8 Windows and macOS installer builds to tcl/t https://bugs.python.org/issue32901 opened by terry.reedy #32902: FileInput "inplace" redirects output of other threads https://bugs.python.org/issue32902 opened by mj4int #32903: os.chdir() may leak memory on Windows https://bugs.python.org/issue32903 opened by izbyshev #32904: os.chdir(), os.getcwd() may crash on Windows in presence of ra https://bugs.python.org/issue32904 opened by izbyshev #32907: pathlib: test_resolve_common fails on Windows https://bugs.python.org/issue32907 opened by izbyshev #32909: ApplePersistenceIgnoreState warning on macOS https://bugs.python.org/issue32909 opened by cbrnr #32910: venv: Deactivate.ps1 is not created when Activate.ps1 was used https://bugs.python.org/issue32910 opened by godaygo #32911: Doc strings no longer stored in body of AST https://bugs.python.org/issue32911 opened by Mark.Shannon #32912: Raise non-silent warning for invalid escape sequences https://bugs.python.org/issue32912 opened by ebarry #32913: Improve regular expression HOWTO https://bugs.python.org/issue32913 opened by JoshuaRLi #32914: python3-config --ldflags gives a CMP0004 error due to a whites https://bugs.python.org/issue32914 opened by kekePower #32915: Running Python 2 with -3 flag doesn't complain about cmp/__cmp https://bugs.python.org/issue32915 opened by trey #32916: IDLE: change 'str' to 'code' in idlelib.pyparse.PyParse and us https://bugs.python.org/issue32916 opened by terry.reedy #32917: ConfigParser writes a superfluous final blank line https://bugs.python.org/issue32917 opened by tttnns #32918: IDLE: make smart indent after comment line consistent https://bugs.python.org/issue32918 opened by terry.reedy #32919: csv.reader() to support QUOTE_ALL https://bugs.python.org/issue32919 opened by Pavel Shpilev #32920: Implement PEP 529 for os.getcwdb on Windows https://bugs.python.org/issue32920 opened by eryksun #32921: .pth files cannot contain folders with utf-8 names https://bugs.python.org/issue32921 opened by einaren #32922: dbm.open() encodes filename with default encoding rather than https://bugs.python.org/issue32922 opened by Josh Friend #32923: Typo in documentation of unittest: whilst instead of while https://bugs.python.org/issue32923 opened by Тимофей Хирьянов #32924: Python 3.7 docs in docs.p.o points to GitHub's master branch https://bugs.python.org/issue32924 opened by Mariatta Most recent 15 issues with no replies (15) ========================================== #32924: Python 3.7 docs in docs.p.o points to GitHub's master branch https://bugs.python.org/issue32924 #32922: dbm.open() encodes filename with default encoding rather than https://bugs.python.org/issue32922 #32921: .pth files cannot contain folders with utf-8 names https://bugs.python.org/issue32921 #32920: Implement PEP 529 for os.getcwdb on Windows https://bugs.python.org/issue32920 #32919: csv.reader() to support QUOTE_ALL https://bugs.python.org/issue32919 #32915: Running Python 2 with -3 flag doesn't complain about cmp/__cmp https://bugs.python.org/issue32915 #32914: python3-config --ldflags gives a CMP0004 error due to a whites https://bugs.python.org/issue32914 #32913: Improve regular expression HOWTO https://bugs.python.org/issue32913 #32907: pathlib: test_resolve_common fails on Windows https://bugs.python.org/issue32907 #32903: os.chdir() may leak memory on Windows https://bugs.python.org/issue32903 #32902: FileInput "inplace" redirects output of other threads https://bugs.python.org/issue32902 #32894: AST unparsing of infinity numbers https://bugs.python.org/issue32894 #32890: os: Some functions may report bogus errors on Windows https://bugs.python.org/issue32890 #32887: os: Users of path_converter don't handle fd == -1 properly https://bugs.python.org/issue32887 #32878: Document value of st_ino on Windows https://bugs.python.org/issue32878 Most recent 15 issues waiting for review (15) ============================================= #32918: IDLE: make smart indent after comment line consistent https://bugs.python.org/issue32918 #32917: ConfigParser writes a superfluous final blank line https://bugs.python.org/issue32917 #32916: IDLE: change 'str' to 'code' in idlelib.pyparse.PyParse and us https://bugs.python.org/issue32916 #32914: python3-config --ldflags gives a CMP0004 error due to a whites https://bugs.python.org/issue32914 #32913: Improve regular expression HOWTO https://bugs.python.org/issue32913 #32907: pathlib: test_resolve_common fails on Windows https://bugs.python.org/issue32907 #32904: os.chdir(), os.getcwd() may crash on Windows in presence of ra https://bugs.python.org/issue32904 #32903: os.chdir() may leak memory on Windows https://bugs.python.org/issue32903 #32901: Update 3.7 and 3.8 Windows and macOS installer builds to tcl/t https://bugs.python.org/issue32901 #32900: Teach pdb to step through asyncio et al. https://bugs.python.org/issue32900 #32893: ast.literal_eval() shouldn't accept booleans as numbers in AST https://bugs.python.org/issue32893 #32890: os: Some functions may report bogus errors on Windows https://bugs.python.org/issue32890 #32888: Improve exception message in ast.literal_eval https://bugs.python.org/issue32888 #32885: Tools/scripts/pathfix.py leaves bunch of ~ suffixed files arou https://bugs.python.org/issue32885 #32882: SSLContext.set_ecdh_curve() not accepting x25519 https://bugs.python.org/issue32882 Top 10 most discussed issues (10) ================================= #32880: IDLE: Fix and update and cleanup pyparse https://bugs.python.org/issue32880 12 msgs #32911: Doc strings no longer stored in body of AST https://bugs.python.org/issue32911 12 msgs #32604: Expose the subinterpreters C-API in Python for testing use. https://bugs.python.org/issue32604 11 msgs #32901: Update 3.7 and 3.8 Windows and macOS installer builds to tcl/t https://bugs.python.org/issue32901 11 msgs #32886: new Boolean ABC in numbers module https://bugs.python.org/issue32886 10 msgs #32846: Deletion of large sets of strings is extra slow https://bugs.python.org/issue32846 8 msgs #32849: Fatal Python error: Py_Initialize: can't initialize sys standa https://bugs.python.org/issue32849 8 msgs #32874: IDLE: Add tests for pyparse https://bugs.python.org/issue32874 8 msgs #32008: Example suggest to use a TLSv1 socket https://bugs.python.org/issue32008 7 msgs #32900: Teach pdb to step through asyncio et al. https://bugs.python.org/issue32900 7 msgs Issues closed (38) ================== #18356: help(numpy) causes segfault on exit https://bugs.python.org/issue18356 closed by csabella #19412: Add docs for test.support.requires_docstrings decorator https://bugs.python.org/issue19412 closed by csabella #21060: Better error message for setup.py upload command without sdist https://bugs.python.org/issue21060 closed by eric.araujo #23462: All os.exec*e variants crash on Windows https://bugs.python.org/issue23462 closed by steve.dower #28339: "TypeError: Parameterized generics cannot be used with class o https://bugs.python.org/issue28339 closed by levkivskyi #28886: Move deprecated abc module decorators to separate section in d https://bugs.python.org/issue28886 closed by inada.naoki #29116: Make str and bytes error messages on concatenation conform wit https://bugs.python.org/issue29116 closed by serhiy.storchaka #30028: make test.support.temp_cwd() fork-safe https://bugs.python.org/issue30028 closed by gregory.p.smith #31333: Implement ABCMeta in C https://bugs.python.org/issue31333 closed by levkivskyi #31848: "aifc" module does not always initialize "Aifc_read._ssnd_chun https://bugs.python.org/issue31848 closed by serhiy.storchaka #31937: Add the term "dunder" to the glossary https://bugs.python.org/issue31937 closed by brett.cannon #31972: Inherited docstrings for pathlib classes are confusing https://bugs.python.org/issue31972 closed by eric.araujo #32016: Python 3.6.3 venv FAILURE https://bugs.python.org/issue32016 closed by csabella #32087: deprecated-removed directive generates overlapping msgids in . https://bugs.python.org/issue32087 closed by inada.naoki #32162: typing.Generic breaks __init_subclass__ https://bugs.python.org/issue32162 closed by levkivskyi #32409: venv activate.bat is UTF-8 encoded but uses current console co https://bugs.python.org/issue32409 closed by steve.dower #32495: Adding Timer to multiprocessing https://bugs.python.org/issue32495 closed by jcrotts #32540: venv docs - doesn't match behavior https://bugs.python.org/issue32540 closed by Mariatta #32566: Not able to run Python 3.6 on Windows https://bugs.python.org/issue32566 closed by steve.dower #32682: test_zlib improve version parsing https://bugs.python.org/issue32682 closed by pmpp #32764: Popen doesn't work on Windows when args is a list https://bugs.python.org/issue32764 closed by steve.dower #32840: Must install python 3.6.3 when 3.6.4 already installed https://bugs.python.org/issue32840 closed by steve.dower #32852: trace changes sys.argv from list to tuple https://bugs.python.org/issue32852 closed by serhiy.storchaka #32858: Improve OpenSSL ECDH support https://bugs.python.org/issue32858 closed by sruester #32859: os.dup2() tests dup3() availability on each call https://bugs.python.org/issue32859 closed by benjamin.peterson #32860: Definition of iglob does not mention single star (unlike glob) https://bugs.python.org/issue32860 closed by Mariatta #32863: Missing support for Emojis in tkinter https://bugs.python.org/issue32863 closed by serhiy.storchaka #32864: Visual glitches when animating ScrolledText instances using pl https://bugs.python.org/issue32864 closed by serhiy.storchaka #32868: python 3 docs' iterator example has python 2 code https://bugs.python.org/issue32868 closed by robotwizard #32869: Incorrect dst buffer size for MultiByteToWideChar in _Py_fopen https://bugs.python.org/issue32869 closed by izbyshev #32870: Documentation typo (2.x only) for deque.remove https://bugs.python.org/issue32870 closed by rhettinger #32889: Valgrind suppressions need updating https://bugs.python.org/issue32889 closed by benjamin.peterson #32895: Make general function sum() use Numpy's sum when obviously pos https://bugs.python.org/issue32895 closed by rhettinger #32898: [BUILD] Using COUNT_ALLOCS breaks build https://bugs.python.org/issue32898 closed by benjamin.peterson #32899: Not documented: key in dict test may raise TypeError https://bugs.python.org/issue32899 closed by rhettinger #32905: IDLE: remove unused code in pyparse module https://bugs.python.org/issue32905 closed by terry.reedy #32906: AttributeError: 'NoneType' object has no attribute 'sendall' https://bugs.python.org/issue32906 closed by steven.daprano #32908: decimal ROUND_HALF_UP not according to spec for 9.95 to 10.0 https://bugs.python.org/issue32908 closed by mark.dickinson

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Dataclasses, frozen and __post_init__
by Jim J. Jewett Feb. 23, 2018

Feb. 23, 2018

On Mon, Feb 19, 2018 at 5:06 PM, Chris Barker - NOAA Federal < chris.barker at noaa.gov> wrote: > If I have this right, on the discussion about frozen and hash, a use > case was brought up for taking a few steps to create an instance (and > thus wanting it not frozen) and then wanting it hashable. > Which pointed to the idea of a “ freeze this from now on” method. > This seems another use case — maybe it would be helpful to be able to > freeze an instance after creation for multiple use-cases? Yes, it would be helpful. But in practice, I've just limited the hash function to only the attributes that are available before I need to stick the object in a dict. In practice, that has always been more than sufficient. -jJ

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